I would like to be a more active user of IRSSI as I am not a big fan of either Pidgin, XChat or mIRC, having used all of them for over a year.

Unfortunately Irssi seems to be unable to connect to IRC. There has been no problem in connecting to http, ftp via command-line in cygwin. I have configured dmz to this computer, but it made no difference.

I have also tried connecting via SSL and trying alternative Freenode servers. I cannot connect to Quakenet and EFNet either, so I assume I cannot connect to any IRC server.